The invention relates to gas turbine combustors and, more particularly, to improvements in gas turbine combustors for reducing air pollutants such as nitrogen oxides (NOx).
Gas turbine engines typically include a compressor section, a combustor section, and at least one turbine section. The compressor compresses air that is mixed with fuel and channeled to the combustor. The mixture is then ignited generating hot combustion gases. The combustion gases are channeled to the turbine, which extracts energy from the combustion gases for powering the compressor, as well as for producing useful work to power a load, such as an electrical generator.
Existing dry low NOx (DLN) combustion systems have a secondary fuel nozzle that provides a flame that supports the primary flame. The fuel/air mixture coming out of the secondary fuel nozzle is not fully premixed and contributes to the NOx production from the gas turbine.
It would be desirable to increase the air/fuel mixedness in the secondary fuel nozzle to enable NOx reduction from the gas turbine.